Apparatus for controlling well production



Feb. 23, 1943. R M RHQADS 2,311,869

' APPARATOs FOR OONTROLLINO WELL PRODUCTION Filed Oct. 1, 1940 v s sheets-sheet 2 Feb. 23, 1943. R M, RHOADS 2,311,869

APPARATUS FOR CONTROLLING WELL PRODUCTION Filed oct. 1, 1940 s sheets-sheet 3 Patented Feb. 23, 1943 APPARATUS FOR CONTROLLING WELL PRODUCTION Roy M. Rhoads, Bellflower, Calif., assignor of one-fourth to Arthur L. Armentrout, onefourth to Elwin B. Hall, and one-fourth to Virgil P. Baker, Los Angeles, Calif.

Application October 1, 1940, Serial No. 359,224

(Cl. 13S-43) 6 Claims.

This invention relates to the control of fluid under pressure and relates more particularly to a method and apparatus for controlling the flow of fluid produced by a well such as an oil well. A general object of the invention is to provide a very efcient and dependable method and a simple, effective apparatus for controlling the flow of well fluid under pressure.

Oil wells often produce fluids under very high pressures and steps must be taken to reduce the pressure so that the fluids may be safely handled by the pipe lines, separators, etc. 'Ihe fluids vary somewhat in character in different Vwells but usually include mainly oil and gas,

with some water, and possibly some sand. Where I use the term fluid I have reference to the fluid or uids such as are produced from oil wells.

It is the general practice to install chokes or flow beans in the production string of an oil well or in the Christmas tree at the top of the well to bring about the desired reduction in pressure. A choke or flow bean of the type formerly employed for this purpose has a short,

restricted passage or orice bringing about a` reduction in the pressure at the outlet end of the bean. The velocity of the fluid is greatly increased in the restricted passage or orifice and there is considerable fluid turbulence at the bean. If the well fluid contains water, the high velocity of the oil and water in the restricted passage of the ordinary flow bean results in a mixing action which emulsiies a part or all of the fluid depending upon existing conditions. Ordinarily before such production or fluid is delivered to the pipe line or storage tanks it must be subjected to an emulsion breaking process. In addition to this undesirable emulsion-producing action of the conventional chokes or flow beans, devices of this kind quickly cut out through the action of the abrasive solid matter such' as particles in the well fluids, and require frequent repairs and replacements.

An important object of the present invention is to provide a method for controlling the flow of well fluids which reduces the pressures Without emulsifying the fluid.

Another object of this invention is to provide a method for controlling the flow of well fluids to bring about a controlled reduction in the pressure which is characterized by a gradual substantially uniform reduction in the pressure.

Another object of this invention is to provide a flow controlling method of the character referred to which is variable or controllable to bring about a selected or required reduction in the uid pressure. l

Another object of this invention is to provide a novel, highly effective apparatus for controlling a flowing well such as an oil well, which operates to reduce the pressure Without emulsifying the fluids.

Another object of this invention is to provide a ow controlling apparatus for oil wells and the like that is long wearing and affected to a minimum degree by the abrasive action of the solid matter particles in the well fluid.

Another object of this invention is to provide an apparatus of the character referred to that produces a substantial reduction in the fluid pressure without appreciably or suddenly reducing the temperature of the fluid. 'Ihis feature of the invention adapts the apparatus for the handling of mixed gases and liquids and moisture bearing gases of the kind produced by wells which are often subjected to a solidifying action or ice-forming action in the conventional chokes or flow beans.

Another object of this invention is to provide an apparatus of the character mentioned capable of safely and dependably handling fluids under very high pressures and which is operable to bring about pressure reductions to permit safe handling of the fluids by conventional ,of carrying out the method and typical forms of apparatus of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is an elevation view of one form of apparatus of the invention showing the coiled conductor in an extended condition. Fig. 2 is a view similar to Fig. 1 'illustrating another embodiment of the invention. Fig. 3 is a view similar to Fig. l showing still another form of the invention. Fig. 4 is an enlarged fragmentary detailed sectional view of a portion of the apparatus illustrated in Fig. 3 showing one of the connections between the conductor sections with one of said sections appearing in side elevation, Fig. 5 is a fragmentary elevation taken substantially as indicated by line 5 5 on Fig. 4 with the pressure gauge fitting in cross section, and Fig'. 6 is an elevation View of another form of theinvention. Figs. 1 and 2 of the drawings, illustrate typical forms of apparatus of the invention which are fixed in their action or incapable of regulation while Figs. 3, 4 and 5 illustrate a typical form of the invention which may be readily adjusted or regulated. It will be assumed that in each instance the apparatus is connected with a part of the fluid handling equipment at the top of the well, for example at the well head or Christmas tree of an oil well, and this element or part will.

be termed the well head IIJ, it being understood that the apparatus may be connected with any element of the Well flow handling equipment and that the invention is not to be construed as restricted to the particular mode of installation illustrated.

The apparatus of the invention illustrated in Fig. l of the drawings comprises an elongate fluid conductor I I of limited uid carrying capacity for controlling the flow of fluid under pressure from the Well head IIJ.

The conductor I I is the active unit or element of the apparatus serving to bring about the required or desired reduction in fluid pressure and a desirable control of the fluid volume. As illustrated, the conductor I I may be a single continuous duct, pipe or conduit of substantial length, it being understood that the length of the conductor II depends upon the conditions existing at the particular installation. If desired the conductor II may be a long, straight tubular member. However, the preferred form of the invention contemplates the shaping of the control conductor II into a spiral or coil to conserve space and to make the unit easy to transport, install, etc; As illustrated in the drawingsthe conductor I I may be shaped to have a multiplicity of convolutions of substantially the same diameter. In most cases it may be preferred to shape the conductor II so that its convolutions are in contacting or adjacent relation to reduce the over-all size of the unit to a minimum.V In the drawings the conductor II is shown extended to better illustrate the features of the invention. One end of the flow controlling conductor II is connected with the Well or head I, defined above, while the other end of the conductor is connected with a line or pipe I2 for conveying the fluid from the well. A suitable adapter or tting I3 may connect the inner end of the conductor II with the well head I and a suitable reducer I4 may connect the outer end of the conductor with the pipe I2.

The conductor II is proportioned or formed to gradually and substantially uniformly reduce the pressure of the iluid flowing through it without causing sudden changes in fluid velocity that might cause turbulence. In accordance with the invention the conductor I I is a long conduit of restricted or limited iluid carrying capacity throughout and gradually increasing in cross sectional area or uid carrying capacity from its fluid receiving end to its outlet end. The increase in cross sectional area of the conductor II may be gradual throughout the entire length of the conductor so that the conductor is in eiect, a long, flaring flow controlling element. In most installations the conductor II is small or materially reduced in cross sectional area at its fluid receiving end, that is, its receiving end is considerably smaller in internal diameter than the well head IB or other element delivering fluid to the apparatus. Further, the outlet end of the conductor I I, which is the largest portion of the conductor, is also appreciably smaller in diameter or fluid carrying capacity than the Well head I D. The length of the conductor II, the internal diameter of the conductor I I at its inlet end, and the internal diameter of the conductor II at its outlet end, are determined to a large extent by ductor I I the initial pressure of the iluid, that is the fluid pressure at the head I0, the nal fluid pressure desired, the available installation space, and other factors. Accordingly, the invention contemplates a Wide variation in these dimensions of the con- It may be said that the conductor I I is proportioned to have a length many times Vgreater than its average internal diameter and the average internal diameter of the tapering conductor II is much smaller than the diameter of the fluid pressure source or Well head IIJ.

The apparatus may include suitably positioned pressure gauges for indicating the pressures in diierent parts of the equipment. In the drawings I have shown a number of pressure gauges I5 arranged to communicate with the interior of the conductor II at points spaced along the length thereof. Similar pressure gauges IE and I1 may be provided-on the head I0 and the pipe I2 or the reducer I4. The gauge I6 indicates the initial fluid pressure while the gauge II ndicates the final iluid pressure at the outer end of the conductor I I.

In'employing the apparatus of Fig. l, in accordance with the method of the invention, the fluid under pressure from the Well head I0 flows through the conductor II to the line or pipe I2. The fluid under pressure passing through the conductor II is subjected to the regulating action as provided by the method of the invention. The pressure of the fluid is markedly reduced by the frictional action of the long, restricted conductor II, this pressure reducing action being gradual and substantially uniform throughout the length of the long conductor. This gradual sustained reduction. in the pressure of the fluid is accompanied by a gradual volume increase by virtue of the increased diameter of the conductor II thereby insuring the maintenance of a substantially constant fluid velocity throughout the length of the conductor II. Thus the pressure of the fluid Yis reduced Without a sudden volume change or velocity change. The controlled pressure reduction is characterized by a substantially constant iluid velocity condition and is such that there is no appreciable fluid turbulence, therefore, no emulsication of the fluid. Further, the controlled gradual pressure reduction is accomplished without a sudden decrease in the temperature of the fluid and there is no danger of the equipment becoming clogged with ice or snow.

Fig. 2 of the drawings illustrates a form of the apparatus which is characterized by its sectional construction. The apparatus illustrated in Fig. 2 of the drawings comprises an elongate fluid conductor II8L of limited and gradually increasing uid carrying capacity made up of a number of sections A, B, C, D and E.

The ow controlling conductor IIa is interposed between the head Ill and the pipe I2 and resembles the conductor II in the manner of its installation and in its flow controlling action. The conductor IIa may be a long pipe or conduit that is substantially straight or that has any selected shape. It is preferred, however, to form the conductor IIa in a spiral or coil to make it compact and easy to install. In accordance with this form of the invention the conductor IIEl comprises the multiplicity of sections A to E, inclusive, to reduce its cost of manufacture. The number of sections embodied in the conduit IIa depends upon the intended use or installation. and the lengths of the individual sections A to E, inclusive, may be varied as desired. Each section A to E, inclusive, may have one, two. or more convolutions. In the particular typical arrangement illustrated each section A to E, inclusive, has two convolutions.

The conductor Ile is formed to operate in the same manner as the conductor II, that is, to bring about an extended substantially uniform reduction in the fluid pressure with no sudden change of velocity and with little change in temperature. The conductor IIa is flared or graduated in fluid carrying capacity from one end to the other. The section A constitutes the inlet section and is the most restricted or limited in fluid carrying capacity, the section B is somewhat larger in internal diameter than the section A, the section C is slightly larger in fluid carrying capacity than the section B, the section D is somewhat larger in diameter than the section C and the section E in somewhat larger in di# ameter than the section D. The sections A to E inclusive may be graduated in fluid carrying capacity or internal diameter in a regular progression, or, if desired, the extent of variation in internal diameters may progress in an irregular manner. The extent of variation or progression in the fluid carrying capacities of the sections A to E, inclusive, may be determined by the intended installation of the apparatus. If desired the individual conductor sections A to E, inclusive,

may be flared or gradually increased in internal' diameter from their inlet ends to their outlet ends. However, it is preferred to make the individual sections A to E, inclusive, uniform in internal diameter from one end to the other. The sections A to E, inclusive, are joined in fluid passing relation by suitable couplings I8 that may take the form of reducers. The couplings I8 may be threaded or welded to the adjacent end portions of the conductor sections. If desired, a fluid pressure gauge I9 may be provided on each coupling I8 to indicate the fluid pressures in the connected ends of the sections A to E, inclusive.

The apparatus illustrated in Fig.'2 of the drawings operates in substantially the same manner as the apparatus of Fig. l. The conductor IIat constitutes a long and restricted fluid conduit of gradually increasing diameter that brings about a gradual but substantial reduction in the pressure on the fluid while maintaining the velocity substantially constant, or preventing sudden velocity changes. The controlled, maintained substantially uniform reduction in the fluid pres sure does not result in a rapid breaking up of the liquid particles and there is no emulsiiication of the fluid. Further, the extended and controlled fluid reducing action'does not' produce a sudden or substantial reduction in the temperature of the fluid.

Figs. 3, 4 and 5 of the drawings illustrate an apparatus of the invention that is adjustable or regulable to reduce the iluid pressure to any de# sired extent within its range of action. The apparatus illustrated in Figs. 3, 4' and 5 of the drawings comprises an elongate conductor IIb of limited gradually increasing lluid carrying capacity and constructed for elongation and shortening to vary the pressure reducing action.

In practice the conductor IIb may comprise a plurality of pipe sections or fluid conductor sections A', B', C', D' and E' similar to or identical with the sections A to E, inclusive, of the structure illustrated in Fig. 2. The number of sections provided and the effective diameters or internal diameters of the vsections vary with dif- CTI ferent installations of the apparatus. The sec-v tions A' to E', inclusive, are graduated in internal diameter or fluid carrying capacity from the inlet end of the conductor Ilb to the outlet end. Thus the section A' has the smallest uid carrying capacity or internal diameter while the section E' has the largest internal diameter. In this form of the invention the sections A' to E' are related so that their end portions are in slidable or shiftable telescopic relation. The upper or outer end portion of the section A' is telescopically received in the inner or lower end portion of the section B', the upper end portion of the section B is telescopically received in the inner or lower end portion of the section C' and so on throughout the series of sections. Suitable packing glands 20 or other sealing means are provided on the outer telescopically engaged portions of the conductor sections to seal about the inner telescoping parts to prevent the leakage of fluid under pressure from between the sections.

The invention may include means for releasably locking or holding the sections A' to E', inclusive, against relative shifting so that the high fluid pressure which may be handled by the apparatus, cannot change the setting or adjustment of the sections. This means may comprise collars 2| welded or otherwise fixed to the outer telescoping portions of the sections A to E', inclusive, and sleevesl 22 engaged around the eX- posed portions of the adjacent sections. Webs 23 extend between `and connect the collars 2l and the sleeves 22 to make the sleeves rigid with the collars. The webs 23 may be bowed outwardly to pass the packing glands 20 with suitable clearance. The sleeves 22 are split and are formed to permit relative shifting of the sections. Screws or bolts 24 are arranged through openings in the split portions of the sleeves 22 and are adapted to be tightened to clamp the sleeves on their respective conductor sections. With the sleeves 22 securely clamped to their respective conductor sections-*by the bolts 24 the sections are dependably held against relative shifting or telescoping action.

The apparatus illustrated in Figs. 3, 4 and 5 of the drawings operates in the same manner as the other embodiments of the invention. When it is desired to regulate or vary the pressure reducing action of the apparatus one or more of the bolts 24 are loosened to permit relative movement of the desired sections of the conductor I Ib for the purpose of decreasing or increasing the length thereof. In some cases it may be desiredv to increase or decrease the effective length of only a portion of the conductor IIb, in which case one or two of the sleeves 22 in the selected portion of the conductor are freed by loosening their bolts 24 so that the adjacent sections may be shifted. In other cases, it may be desired to adjust the conductor I Ib throughout its length and the conductor is conditioned for this operation by loosening the several bolts 24. Increasing the length of the conductor I Ib increases the pressure reducing action of the apparatus while decreasing the effective length of the conductor IIb decreases the pressure reducing action.

Where the'sections A to E, inclusive, of the conductor IIb are coiled or helically curved, as described and illustrated, the adjustments of the conductor may be accomplished with a minimum change in the actual length of the conduc-tor requiring a minimum change in position of the pipe I2 with respect to the head I0. The flow controlling apparatus illustrated in Figs. 3, 4 and 5 of the drawings may be adjusted or regulated to adapt it for use in any given situation or to compensate for changes in conditions at the well, and its adjustable sections may have suitable pressure gauges to indicate the pressure reducing action and the result of such regulation.

In Fig. 6 I show another form of structure that may be employed in carrying out my invention. In this case the conductor l IX is in the form of a long tube or pipe of small size or carrying capacity. The conductor HX is continuous and substantially uniform in size throughout. In this case as in those previously described, the conductor may be shaped into a convenient form and may be provided at suitable intervals with pressure gauges.

Having described only typical preferred manners of carrying out the method and typical forms of apparatus of my invention, I do not Wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

l. Apparatus for controlling the flow of a fluid which increases in volume when subjected to a pressure drop, comprising two or more coiled tubular units assembled to form an unobstructed conduit connected to a well or other source of fluid under pressure, the fluid carrying capacity of the conduit being so proportioned to the pressure head and the viscosity of the fluid as to permit fluid at a predetermined gravimetric rate to pass through the conduit at a predetermined approximately uniform velocity, the cross sectional area of the second and each subsequent unit in the direction of flow being sufciently greater than the cross sectional area of the preceding unit to accommodate the changing volume of the fluid whereby the predetermined velocity is maintained approximately uniform.

2. Apparatus for controlling the flow of a fluid which increases in volume when subjected to a pressure drop, comprising an unobstructed conduit connected to a Well or other source of fluid under pressure, said conduit being composed of two or more connected coiled tubular units, the cross sectional area of the second and each subsequent unit in the direction of flow being greater than the cross sectional area of the preceding unit to accommodate the changing volume of the fluid, said conduit being so proportioned to the pressure head, the viscosity of the fluid and the changing volume of the fluid as to permit iluid at a predetermined gravimetric rate to pass through the conduit at a predetermined approximately uniform velocity whereby the volume of fluid discharged at the outflow end of the conduit and the pressure of the fluid thereat are controlled.

3. Apparatus for controlling the flow of a fluid which increases in volume when subjected to a pressure drop, comprising an unobstructed conduit connected to a Well or other source of fluid under pressure, said conduit consisting of connected coiled sections, the cross sectional area of each section in the direction of flow being larger than the cross sectional area of the preceding section to accommodate the changing volume of fluid, each section being so proportioned to the pressure head, the viscosity of the fluid and the changing Volume of the fluid as to permit uid at a predetermined gravimetric rate to pass through all of the sections at a predetermined approximately uniform velocity whereby the volume of fluid discharged at the ellluent end of the conduit and the pressure of the fluid thereat are controlled.

4. Apparatus for controlling the flow of a fluid which increases in volume when subjected to a pressure drop, comprising an unobstructed conduit connected to a Well or other source of fluid under pressure, said conduit being composed of two or more connected coiled tubular units, the cross sectional area of the second and each subsequent unit in the direction of flow being greater than the cross sectional area of the preceding unit to accommodate the changing volume of the fluid, said conduit being so proportioned to the pressure head, the viscosity of the fluid and the changing volume of the fluid as to permit fluid at a predetermined gravimetric rate to pass through the conduit at a predetermined approximately uniform velocity whereby the volume of uid discharged at the outflow end of the conduit and the pressure of the fluid thereat are controlled, at least one of the tubular units being telescopically arranged in another tubular unit and movable with respect thereto to vary the effective length of the conduit.

5. Apparatus for controlling the flow of a fluid which increases in volume when subjected to a pressure drop, comprising an unobstructed coiled conduit connected to a well or other source of fluid under pressure, said conduit being composed of two or more connected tubular units, the cross sectional area of the second and each subsequent unit in the direction of flow being greater than the cross sectional area of the preceding unit to accommodate the changing volume of the fluid, said conduit being so proportioned to the pressure head, the viscosity of the fluid and the changing volume of the fluid as to permit fluid at a predetermined gravimetric rate to pass through the conduit at a predetermined approximately uniform velocity whereby the volume of fluid discharged at the outflow end of the conduit and the pressure of the fluid thereat are controlled, at least one of the tubular units being telescopically arranged in another tubular unit and movable with respect thereto to vary the effective length of the conduit, means for sealing between the relatively movable units. and means for controlling the movement of the respective members of the telescopic unit.

6. Apparatus for controlling the flow of a fluid which increases in volume when subjected to a pressure drop, comprising an unobstructed conduit connected to a well or other source of fluid under pressure, said conduit consisting of connected coiled sections, the cross sectional area of each trailing section being larger than the cross sectional area of the preceding section to accommodate the changing volume of uid, each section being so .proportioned to the pressure head, the Viscosity of the fluid and the changing volume of the fluid as to permit fluid at a predetermined gravimetric rate to pass through all of the sections at a predetermined approximately uniform velocity whereby the volume of fluid discharged at the effluent end of the conduit and the pressure of the iluid thereat are controlled, the connected sections being telescopically related whereby the effective length of the conduit may be increased or decreased.

ROY M. RHOADS. 

